Reading School of Pharmacy, University of Reading, Reading RG6 6AD, UK.
Reading School of Pharmacy, University of Reading, Reading RG6 6AD, UK.
Int J Pharm. 2021 Jan 25;593:120130. doi: 10.1016/j.ijpharm.2020.120130. Epub 2020 Nov 29.
Targeting drug delivery to hair follicles is valuable to treat conditions such as alopecia's and acne, and this shunt route may also allow drug delivery to deeper skin layers and the systemic circulation by avoiding the intact stratum corneum. Here, we investigated the effects of nanoparticle surface chemistry on their delivery into hair follicles by synthesizing fluorescent thiolated silica nanoparticles and functionalizing with 750 Da and 5000 Da methoxypolyethylene glycol maleimide (PEG). The stability of the nanoparticles in skin homogenate was verified before tape stripping of porcine-dosed tissue showed the distribution of the free fluorescent dye and different nanoparticles in the skin. Analysis of microscopic images of the skin sections revealed penetration of nanoparticles functionalized with PEG into the appendages whereas thiolated nanoparticles stayed on the surface of the skin and were removed by tape stripping. Nanoparticles functionalized with PEG 5000 Da penetrated deeper into the hair follicles compared to counterparts functionalized with PEG 750 Da. PEGylation can thus enhance targeted delivery of nanoparticulates into hair follicles.
将药物递送到毛囊对于治疗脱发和痤疮等疾病非常有价值，而且这条旁路途径还可以通过避免完整的角质层将药物递送到更深的皮肤层和全身循环中。在这里，我们通过合成荧光硫醇化硅纳米粒子并分别用 750 Da 和 5000 Da 的甲氧基聚乙二醇马来酰亚胺（PEG）对其进行功能化，研究了纳米粒子表面化学对毛囊内递药的影响。在对猪给药组织进行胶带剥离之前，验证了纳米粒子在皮肤匀浆中的稳定性，结果显示游离荧光染料和不同纳米粒子在皮肤中的分布。皮肤切片的显微镜图像分析表明，PEG 功能化的纳米粒子能够进入附属物，而硫醇化纳米粒子则停留在皮肤表面，并通过胶带剥离去除。与 PEG 750 Da 功能化的纳米粒子相比，PEG 5000 Da 功能化的纳米粒子能够更深地渗透到毛囊中。因此，PEG 化可以增强纳米颗粒靶向递送到毛囊中的效果。
